Die guide and work-straightening device



Aug. 30, 1960 A. KREIDLER 2,950,811

DIE cum: AND WORK-STRAIGHTENING DEVICE Filed June 3. 1952 2 Sheets-Sheet 1 Aug. 30, 1960 Filed June 3. 1952 2 Sheets-Sheet 2 lA/Vi/YIOP DIE GUIDE AND WORK-STRAIGHTENING DEVICE Alfred Kreidler, Gaensheidestrasse (14a), Stuttgart, Germany Filed June 3, 1952, Ser. No. 291,372 Claims priority, application Germany June 5, 1951 1 Claim. (Cl. 2053) This invention concerns the production of trued work by drawing.

Straight bars, sections, pipes or the like have hitherto been manufactured in at least three operational stages; namely, drawing on the drawbench, setting up on a trueing machine usually working with straightening rollers, and finishing on trueing and polishing machines. For this purpose three machines with appropriate personnel were necessary. Furthermore there was the transport problem of conveying the work between the individual machines. Thus, with the processes of the prior art, a considerable amount of labour, material and time was necessary. In addition to this, changes in dimension of the work frequently occurred in the tracing as a result of rolling up or of one-sided pressure. Furthermore, sections and pipes in particular were easily crushed or their edges broken. If it was desired to avoid such damage trueing pressure had to be of very limited amount so that frequently straight bars, sections or pipes could not be obtained at all with a single draught and several straightening passes had to be made. By combining the various working means into one single machine unit personnel and conveying costs can certainly be reduced, but the other disadvantages are not thereby avoided.

In fundamental contrast to the previous methods of working the invention permits drawing and trueing in one single operation in such a way that ready drawn and trued bars, pipes of the like are produced which no longer need any further subsequent work-apart from polishing and other surface treatment.

It is, therefore, one object of the present invention to subject the work to a, preferably periodic, varying bending action in the cross section of the passage of the die. It is advisable to do this in such a Way that the work in its course to the die is given a circular motion, preferably round the drawing axis, such that it describes a rotary plane with the point thereof within the die.

It is another object of the present invention to provide an apparatus for carrying out the process according to the invention which can be constructed in various ways. A favourable arrangement is one in which a work guide nozzle is coupled to the die and of which the centre of gravity of the transverse section area rotates by suitable driving and controlling means on an orbit of adjustable radius.

It is still another object of the present invention to provide another no less favourable solution according to which once again a work guide nozzle is coupled to the die but which is adjustably secured in a rotatable driving member, e.g. by hearing bolts and set screws at an angle to the drawing axis.

It is yet another object of the present invention to provide an apparatus in which as the work is to be subjected only to an alternating bending action, but not to a turning, to equip the guide nozzle, for the drawing of section bars with an insert freely rotatable in the guide nozzle of which the passage opening corresponds to the cross section of the work. The insert can of course be omitted in the case of work with a circular cross section.

With these and other objects in view, which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

Figure 1 is a view of such an apparatus seen in the direction of drawing;

Fig. 2 is a section along the line 11-11 of Fig. 1;

Fig. 3 is a view of a difierently constructed apparatus also seen in the direction of drawing, and

Fig. 4 is a section along the line IV-IV of Fig. 3.

Referring now to the drawings and in particular to Figs. 1 and 2, the die 1 is mounted on the die holder 2 by bolts 3 in the usual way. A support 5 is attached to the die holder by spacer bolts 4. A guide nozzle holder 6 is mounted in the support 5 so as to be displaceable with its driving pulley 7 by a belt or cable drive from a separate electric motor or from the drive from the drawbench in rotation (not shown). In the embodment illustrated in Figs. 1 and 2 the guide nozzle 8 in its holder 6 is displaceable in a straight guide 6 perpendicularly to the drawing axis. Its displacement and fixing is effected by set screws 9. An insert 10 is housed so as to be freely rotatable in the guide nozzle 8. The aperture of the insert corresponds in its cross section to the section of the work 11 (a hexagonal bar in the example drawn).

The bar 11 is pushed through the guide nozzle 8, N and with its point through the die 1 and seized in the known Way by tongs (not shown). The guide nozzle 8, 10 is now laterally displaced by means of the set screw 9 in its guide 6' so that the centre point M of its passage area round the space r is displaced out of the drawing axis. The amount of displacement depends on the work and can be obtained from case to case by trial and error. If now during the drawing process the guide nozzle holder 6 is rota-ted, the point M describes a circular motion round the drawing axis and the bar 11 moves in its section approaching the die 1 in a kind of conical covering surface the point of which is situated in the die.

In this way the bar 11 is subjected to a periodic alternating deflection around the passage area X of the die where reduction takes place, the insert 10, however serving to prevent the work from twisting about its longitudinal axis.

Referring now to the embodiment disclosed in Figs. 3 and 4, the guide nozzle 8' is pivotably mounted in its holder 6 by means of bearing bolts 12 and can be set by set screws 13 at an angle as indicated in Fig. 4 by chain dotted lines. As the example illustrated here concerns the drawing of round bars, the insert Ill of the previous example is omitted.

In rotating the guide nozzle holder 6 during the drawing operation the rod 14 descrbes a rotary plane the point of which is once more disposed in the die 1 so that the bar in this case also is subjected to an alternating beiding in the draw nozzle area X.

By alternating bending action in the die area in conjunction with the drawing operation itself the bars are simultaneously drawn and trued so that in one single operation perfectly trued bars are produced, thereby eliminating any separate subsequent trueing.

While I have disclosed two embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

I claim:

A drawbench for producing ready trued work such as bars, pipes and the like, comprising a die holder having a bore to receive said work therethrough, a die having a die-opening and means for removably securing said die to said die holder, a support disposed substantially paral lel to and spaced apart from said die holder, at least two spacer bolts maintaining said support at a predetermined distance from said die, said support having a central opening, a guide nozzle holder having a shoulder engaging one of the end faces of and rotatably mounted in said central opening of said support, a driving pulley mounted on said guide nozzle holder, a guide nozzle adjustably mounted in said guide nozzle holder and receiving said work, and set screws projecting through said guide nozzle holder and retaining said guide nozzle in any one of a plurality of selected positions relative to said guide nozzle holder.

References Cited in the file of this patent UNITED STATES PATENTS Algeo May 10, Brightman Jan. '3, Conlon Oct. '7, Olson Nov. 19, Hudson Feb. 20, Thaden Mar. 3, Gaines et al. Feb. 9, Gaines et al Dec. 28, Anderson Nov. 27, Williams et al. Mar. 9, Kehl Nov. 8, Rosenthal Sept. 18,

FOREIGN PATENTS Great Britain Feb. 9, Great Britain July 22, 

